nuked fluidcodex

src/net/torvald/terrarum/tests/FixedMathTest.kt

@@ -0,0 +1,62 @@
+import kotlin.system.measureNanoTime
+
+/**
+ * Created by minjaesong on 2019-01-27.
+ */
+
+class FixedMathTest {
+    fun invoke() {
+        val testSet = (1..100000).toList().shuffled()
+        val m1 = measureNanoTime {
+            testSet.forEach {
+                val x = (it * 1.41421356f)
+            }
+        }
+        val testSet2 = (1..100000).toList().shuffled()
+        val m2 = measureNanoTime {
+            testSet2.forEach {
+                val x2 = it.mulSqrt2()
+            }
+        }
+        val m3 = measureNanoTime {
+            testSet.forEach {
+                val x = (it * 1.41421356f)
+            }
+        }
+        val m4 = measureNanoTime {
+            testSet2.forEach {
+                val x2 = it.mulSqrt2()
+            }
+        }
+
+        println(m3)
+        println(m4)
+        println(m3.toDouble() / m4)
+    }
+
+    fun Int.mulSqrt2(): Int {
+        val xl = this
+        val yl = 92681
+
+        val xlo = xl and 0x0000FFFF
+        val xhi = xl shr 16
+        val ylo = yl and 0x0000FFFF
+        val yhi = yl shr 16
+
+        val lolo = xlo * ylo
+        val lohi = xlo * yhi
+        val hilo = xhi * ylo
+        val hihi = xhi * yhi
+
+        val loResult = lolo shr 16
+        val hiResult = hihi shl 16
+
+        val sum = loResult + lohi + hilo + hiResult
+        return sum
+    }
+}
+
+fun main(args: Array<String>) {
+    FixedMathTest().invoke()
+}
+